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Biomedical subjects

P J Crawford

Publications and source records attributed to P J Crawford.

At least 19 recordsLinked to original sources
PubMed2002

Epidemiology of adult brain tumours in Great Britain and Ireland.

The objective of this study was to review published reports on the epidemiology of primary brain tumours in adults and present the body of knowledge related to these tumours in Great Britain and Ireland. A literature search of all published epidemiological data on brain tumours was conducted in Pre-Medline, Medline, Embase and the Cochrane databases from 1966 to the present. A hand search of all the references alluded to was conducted and older studies identified. The articles were reviewed and tabulated. The papers were subjected to descriptive analysis. Information available to the public and held with the Cancer Registries was reviewed, and cross-referenced with published evidence. To our knowledge, only seven papers have discussed the epidemiology of primary brain tumours in adults. The different methodology of the population-based studies of brain tumours and the different time periods they investigated makes them incomparable. Two papers with comprehensive and detailed strategies for case ascertainment have both recorded tumour incidences of 21 per 100,000 person years. The results of the better studies are at variance with reports from the Cancer Registries. On the basis of the current studies, Cancer Registries appear to under-estimate the incidence of such tumours in adults. It is apparent that a significant number of tumours especially benign varieties are not recorded by some Cancer Registries. The previous estimates, patterns of incidence, prevalence, and survival of brain tumours in Great Britain and Ireland, may thus be incorrect. Patterns of primary brain tumours in adults have not been widely reported in GB and Ireland and the aetiology remains largely unknown. The need for current estimation of geographical and secular variations was identified. This demands closer co-operation between medical and allied staff, and the Cancer Registries. Prospective regional studies of incidence patterns and up to date epidemiological appraisal is deemed necessary. Meanwhile, Cancer Registries should seriously consider the inclusion of all primary brain tumours in their database.

Adolescent↗
PubMed2001

The management of supernumerary teeth in childhood--a retrospective study of practice in Bristol Dental Hospital, England and Westmead Dental Hospital, Sydney, Australia.

This study compared the treatment provided for patients with supernumerary teeth in Bristol Dental Hospital with those in Westmead Dental Hospital, Sydney, Australia. The records of 63 children referred for removal of a supernumerary tooth in Bristol and 96 children in Westmead were examined, involving a total of 215 supernumerary teeth. Differences in the treatment provided for these patients were found not only between the two centres but also within one centre. There appeared to be no standardised route by which these patients were seen and therefore no standardised pattern of treatment. Contact with all UK Dental Schools indicated that no formal treatment protocol existed for the treatment of children with supernumerary teeth. In addition, a permanent incisor associated with a conical supernumerary tooth was twice as likely to erupt spontaneously as one associated with a supernumerary of tuberculate form. The location of the supernumerary tooth also influenced the likelihood of spontaneous eruption of the associated permanent incisor. There is a need for a prospective randomised controlled trial in the future in order to develop a formal treatment protocol for the management of patients with supernumerary teeth. A multicentre trial is under development.

Adolescent↗
PubMed2001

From here to accountability: securing healthy rivers.

While specifying "responsibilities" for river planning and management implies that outcomes are desired, defining "accountabilities" demands that results are achieved. This paper examines innovative ways of converting aspirations to results, with particular reference to the changes initiated in New South Wales in response to the establishment of the Healthy Rivers Commission of New South Wales and its first round of inquiries.

Conservation of Natural Resources↗
PubMed2001

Tooth extraction, bleeding and pain control.

Local anaesthesia is used routinely in dental surgery; it is effective in both pain control and--through the vasoconstrictors often contained within it--the reduction of bleeding. The extraction of deciduous teeth under general anaesthesia is often carried out without these local effects. There are no previous studies to investigate the combined effect of local anaesthesia with general anaesthesia on blood loss and pain control. A randomised, controlled clinical trial was carried out with one hundred children aged 3-5 years. Ethical approval and informed consent were obtained. Surface anaesthetic cream (EMLA) was placed on the hand into which the intravenous access was to be placed. One to two ml of blood was taken at the time of induction as a baseline of the patient's level of haematin pigment. Children in the experimental group were given one quarter of a cartridge (0.5 ml) of local anaesthetic containing epinephrine (1:80,000) in each quadrant before tooth extraction; all blood in swabs, suction equipment and disposables was collected and digested with NaOH. The children were observed for 11 minutes post-operatively for any signs of distress. Total blood loss was calculated by comparison of the baseline sample and the shed blood digests. This study showed that using local anaesthesia for dental extractions under general anaesthesia was associated with decreased blood loss (p = 0.001). The second finding--which has not been reported before--was that this use of local anaesthesia was shown to cause distress to this age group of children upon recovery from the general anaesthetic (p <0.0001). The use of local anaesthetic in this situation provided a useful reduction in post-operative bleeding. However, its use was associated with greater post-operative distress.

Analgesics↗
PubMed1999

Tricho-dento-osseous syndrome and amelogenesis imperfecta with taurodontism are genetically distinct conditions.

Amelogenesis imperfecta of the hypomaturation-hypoplasia type with taurodontism (AIHHT) is inherited as a highly penetrant autosomal dominant trait. These dental findings are similar to those of another autosomal dominant condition, the tricho-dento-osseous syndrome (TDO), from which AIHHT differs primarily by lack of changes in the hair and bones. TDO is characterized by a highly variable clinical phenotype. While enamel hypoplasia and taurodontism appear to be present in all TDO cases, non-dental features may be absent, with approximately half of TDO cases losing the kinky/curly hair phenotype seen in infancy by adolescence, and in almost 20% of cases, osseous changes are not evident. The genetic basis for AIHHT is unknown and it has been questioned whether AIHHT and TDO are separate conditions or a spectrum of disease. The genetic basis for TDO has recently been identified as a deletion mutation in the distal-less 3 (DLX3) transcription factor gene. To determine if AIHHT and TDO represent variable expression of a common DLX3 gene mutation, allelic mutations of the DLX3 gene, or mutations in DLX7 (the linked paralogue to DLX3 on chromosome 17), we have performed mutational analysis and sequencing studies of the DLX3 and DLX7 genes in three individuals (two affected and one unaffected) from a family with AIHHT. Results of the analysis demonstrate that AIHHT and TDO are not due to a common DLX3 gene mutation. Sequence analyses of the DLX3 and DLX7 genes suggest AIHHT is not due to genetic mutations or polymorphisms in the exons of these genes. These results suggest that AI-HHT and TDO are two genetically distinct conditions.

Abnormalities, Multiple↗
PubMed1998

A randomised trial of calcium alginate swabs to control blood loss in 3-5-year-old children.

OBJECTIVE: To compare the effectiveness of calcium alginate swabs and traditional cotton swabs in the control of blood loss after extraction of deciduous teeth from healthy children, aged 3-5 years, under general anaesthetic. DESIGN: Prospective, randomised clinical trial. SETTING: General anaesthetic suite in a dental teaching hospital. SUBJECTS: 101 patients were recruited to the study, comprising 50 randomised to be treated with cotton swabs and 51 with alginate swabs. INTERVENTIONS: Teeth were extracted under general anaesthesia and blood collected for measurement in order to compare blood loss using the two systems. MAIN OUTCOME MEASURES: The number of teeth extracted ranged from 1-14. The total blood loss ranged from 0.53-78.13 ml with a median of 12.9 ml. CONCLUSION: Calcium alginate swabs were not found to produce any clinical or statistical advantage over traditional cotton swabs in this surgical setting.

Alginates↗
PubMed1997

Molecular biology of hereditary enamel defects.

Amelogenesis imperfecta is a disfiguring inherited condition affecting tooth enamel. X-Linked and autosomal dominant and recessive inheritance patterns occur. X-Linked amelogenesis imperfecta has been studied extensively at the molecular level. Linkage analysis has shown that there is genetic hetetogeneity in X-linked amelogenesis imperfecta with two identified loci: AIH1 and AIH3. The AIH1 locus corresponds to the location of the amelogenin gene on the distal short arm of the X chromosome; various mutations in the amelogenin gene have been found in families with X-linked amelogenesis imperfecta. The AIH3 locus maps to the Xq24-q27.1 region on the long arm of the X chromosome. Linkage to the long arm of chromosome 4 has been established in three families with autosomal dominant amelogenesis imperfecta. There is as yet no published evidence for genetic heterogeneity in autosomal dominant amelogenesis imperfecta as in X-linked amelogenesis imperfecta. Candidate genes for autosomal dominant amelogenesis imperfecta include tuftelin (1q), albumin (4q) and ameloblastin (4q) but the involvement of these genes in the disease has yet to be demonstrated. In view of the variable clinical appearances within families with autosomal dominant amelogenesis imperfecta and X-linked amelogenesis imperfecta, together with the finding that different X-linked amelogenesis imperfecta phenotypes result from mutations within the same gene, an alternative classification based on the molecular defect and mode of inheritance rather than phenotype has been proposed.

Amelogenesis Imperfecta↗
PubMed1997

Recreational overdosage of carbamazepine in Paisley drug abusers.

Oral drug abuse is a major social and medical issue. Paisley, in the West of Scotland, has become infamous for its problem with oral temazepam abuse. With the crack down on the prescription of temazepam in our area and the resultant lack of its supply on the streets, drug abusers appear to be experimenting with new drugs for their psychotropic effects. We report five cases of recreational carbamazepine overdosage in young temazepam abusers.

Adult↗
PubMed1997

Microvascular reconstruction of complex craniofacial defects.

Many large vault or skull base tumours are best treated by wide surgical excision and primary reconstruction using a microvascular free tissue transfer (free flap). We report 23 patients who were reconstructed using free flaps, eight having been previously treated surgically elsewhere and seven of whom had recurrent disease after radiotherapy. There was one flap failure and a local recurrence rate of 16% (3/19). The outcome at a mean follow-up period of 29 months, was 19 patients alive and four deaths.

Adult↗
PubMed1997

Blood loss following extraction of deciduous teeth under general anaesthetic.

The potential for significant blood loss following deciduous tooth extractions has been a factor in treatment planning in dental care for children. This paper reports the results of a study which aimed to quantify normal blood loss following extraction of deciduous teeth from medically fit children under general anaesthetic. Blood loss from a group of 50 children aged 3 to 5 years, having at least one molar tooth removed, was determined by comparing the amount of haemoglobin in a sample of the patient's whole blood with a known dilution of blood collected during surgery and recovery. Total blood loss ranged from 2.5 to 57 mL, with the maximum corresponding to deciduous clearance of (the removal of all deciduous teeth from) the upper arch together with the lower molars for a 3-year-old child. Clinical judgement would suggest that the maximum potential blood loss resulting from a complete dental clearance (20 teeth) from an otherwise fit child in this age group is unlikely to be greater than 100 mL. It is concluded that the risk of inducing hypovolaemic shock from this procedure is much lower than the risks of using repeated administrations of general anaesthesia to facilitate a staged dental clearance.

Anesthesia, General↗
PubMed1996

Craniocervical bone pneumatisation.

We report a case of extensive craniocervical bone pneumatisation presenting after minor trauma. The patient had neurological signs and initial radiographs showed multiple lucencies in the skull base and the atlas vertebra. CT established the true nature of this rare condition.

Athletic Injuries↗
PubMed1996

The oro-facial manifestations of trisomy 8 mosaicism: a case report.

Trisomy 8 mosaicism is a relatively common autosomal chromosomal disorder characterized by features such as mental retardation, characteristic facies, skeletal abnormalities and congenital heart disease. The case of a 4-year-old boy is described with particular reference to the oro-facial manifestations, which included cleft palate, pronounced anterior open bite, complete reserved unilateral buccal cross-bite, slightly increased width of alveolar processes, and gingival enlargement.

Child, Preschool↗